In 1846 Congress established the Smithsonian Institution, an organization
dedicated to the “...increase and diffusion of knowledge.”
At this time Congress transferred the National Cabinet of Curiosities
to the nascent institution. Part of the act of Congress that created
the Smithsonian also mandated that “...all of objects of natural
history, plants, and geological and mineralogical specimens belonging
or hereafter to belong to the United States” would become
the property of the Smithsonian Institution. This made it a Trust
Entity, to act on behalf of the United States as the national treasury
for its official objects. The Institution’s first building,
commonly known as “The Castle”, was completed in 1855,
and housed all Smithsonian operations and collections.

In 1879 the Sundry Civil Act further expanded the role of the Institution
so that “...all collections of rocks, minerals, soils, fossils,
and objects of natural history, archaeology, and ethnology, made
by the Coast and Interior Survey, the Geological Survey, or by any
other parties for the government of the United States, when no longer
needed for investigations in progress, shall be deposited in the
National Museum.” The Arts and Industries building has the
special designation as the original United States National Museum.
This building opened in 1881 and was the home of the first exhibition
of the Section of Vertebrate Paleontology.

Prior to 1870, many of the early vertebrate fossils collected
by the Smithsonian and other government agencies were sent to Dr.
Joseph Leidy in Philadelphia. Leidy is considered to be the “father”
of American vertebrate paleontology for the United States, and described
many of the first dinosaur fossils found in the United States. His
most famous discovery was that of the hadrosaurid Hadrosaurus,
at Haddonfield, New Jersey. As the first dinosaur skeleton found
in the U. S., it formed the basis for a full-scale model by sculptor
Waterhouse Hawkins. One such model stood in the Smithsonian’s
first paleontological exhibit, alongside a model of the ground sloth
Megalonyx.